1. Field of the Invention
The present invention relates to a spreader/grader designed to be pulled by a motor vehicle such as a tractor and more particularly pertains to a spreader/grader which utilizes cutting blades that are variable in cutting depth and in angular relationship to a surface being cut through the use of hydraulic adjustment means.
2. Description of the Prior Art
With respect to the development of spreader/graders utilizable with farm tractors, there has long been recognized a need for developing a spreader/grader which has multi-positionable cutting blades and which may be economically and easily manufactured. An early attempt to develop such a spreader/grader is to be found in U.S. Pat. No. 1,487,723, issued Mar. 25, 1924, to Corbitt, wherein there is disclosed a land leveler which may be pulled by a motor vehicle and which has a pair of side runners held together by bracing bars. An arcuate cutting blade is mounted on a rotatable shaft positioned between the side runners, such blade being adjustable to a desired cutting angle by rotating the same about the shaft through the use of a manually operated lever fixedly attached to the shaft. The Corbitt device utilizes but one blade which is adjustable in cutting depth and which is not adjustable at ends thereof with respect to the side rails so as to vary the angular relationship between the blade and the surface being levelled. As such, the Corbitt land leveler is representative of prior art spreader/graders which are severely limited in their flexibility relating to cutting a surface at a desired depth and angle.